Process of finishing metal plates or sheets



WILLIAM MILTON TIIFOBALD, OF WELLSVILLE, OHIO.

PROCESS OF FINISHING METAL PLATES OR SHEETS.

SPECIFICATION forming part of Letters Patent No. 627,023, dated J nine13, 1899.

Original application filed June '7, 1898, Serial No. 682,841. Dividedandthis application filed November 9, 1898. Serial No. 695,978. (Nospecimens.)

To all whom it may concern:

Be it known that LWILLIAM MILTON THEO- BALD, a citizen of the UnitedStates, residing at VVellsville, in the county of Oolumbiana and Stateof Ohio, have invented certain new and useful Improvements in Processesof Finishing Metal Plates or Sheets; and Ido declare the following to bea full, clear, and exact description of the invention, such as willenable others skilled in the art to which it appertains to make and usethe same.

In an application for patent filed by me June 7, 1898, Serial No.682,841, I described a process hereinafter more fully described, and

particularly specified in the claim.

In annealing metal sheets or plates the same are placed upon theannealing pan or bottom and covered by the annealing-box, after whichthe box and pan are luted in the usual manner to prevent the ingress ofair to the sheets or plates,whichwould result in excessive oxidation.The annealing-box and its contents are now charged into a suitablefurnace and brought to the proper or desired degree of heat,approximately l,4.-00 Fahrenheit. This completes the first step of myprocess.

In the second and improved step of my process the metal sheets or platesare taken from the furnace to polishing or smoothing rolls and passedbetween the same, during which time they are exposed to atmospheric airand the temperature lowers to about 900 Fahrenheit and the desireddegree of oxidation takes place. The plates are then covered withanysuitable cover, such as an annealing-box, to prevent further oxidation,and are then charged into a furnace having a temperature less than thetemperature of the sheets when passed between the rolls and allowed tocool in said furnace, thus securinga uniform color.

The furnace receiving the sheets after rolling should be as near aspracticable to the temperature of such sheets or of slightly lowertemperature, its function being to retard the cooling of the sheets andso govern the color thereof, insuring the practically uniform bluecolor.

Having thus described the invention,what I claim, and desire to secureby Letters Patent, is-

The process herein described of preparing metal sheets or plates, whichconsists in annealing said plates free from contact with atmosphericair, cooling the plates free from atmospheric air to a temperatureranging between the annealing degree of heat and about 900 Fahrenheit,then smoothing and polishing said sheets while subjected to theatmospheric air for oxidation, then covering said plates to preventfurther oxidation, then charging said plates into a furnace andsubjecting them to a temperature less than that of the temperature ofthe plates when being smoothed and polished, and then allowing theplates to gradually cool off, thereby securing a uniform color,substantially as set forth.

In testimony whereof I have hereunto set my hand in presence of twosubscribing witnesses.

IVILLIAM MILTON THEOBALD.

IVitnesses:

H. B. WILLsoN, BENJ. G. Gown.

